<meta charset="UTF-8">
<div id="app">
  <p>{{counter}}</p>
  <p j-text="counter"></p>
  <p j-html="desc"></p>
</div>

<script src="myVue.js"></script>

<script>
  const app = new myVue({
    el:'#app',
    data: {
      counter: 1,
      desc: '<span style="color:red">测试</span>'
    },
  })
  setInterval(() => {
    app.counter++
  }, 1000);

</script>